Internal combustion engines are provided with injectors, as for example electro-actuated solenoid injectors that guarantee a high number of pulses at high fuel pressure thanks to a combination of electrical and hydraulic actuation. This kind of injectors is basically made by a high pressure hydraulic valve and a low pressure electro-actuated valve to change hydraulic condition of the first one. Therefore such injectors requires a low pressure circuit to discharge the fuel used for the valves actuation in a fuel return line in order to collect backflow fuel coining out from injectors.
Different solutions have been proposed in the prior art to connect the backflow port of the injectors to the low pressure return line. For example, banjo fittings (also known as banjo bolts or banjo screws) are largely used in the automotive field for providing pipe connections in high pressure circuits. This is a cost and time expensive solution and requires suitable tools to fix the fitting on the devices connected to the pipe system.
A simpler and cheaper solution envisages a straight connector to be introduced in the backflow port of an injector and a retaining metal clip for latching the connector to the injector. However, this solution does not guarantee error proofing during assembly and service operations.